Objective: To develop a new type of tail cap for closing the tail of the central hole of the interlocking intramedullary nail so as to reduce difficulty in implantation of the tail cap into intramedullary nail, and ensure the accuracy of implantation, as well as reduce unnecessary operation time.
Methods: In 2014, the new type of intramedullary nail tail cap ("new tail cap" for short) was successfully developed, and has been granted national utility model patent. A randomized controlled clinical trial was conducted in 34 patients with non pathological femoral shaft fractures treated between August 2014 and March 2016. The patients were randomly divided into groups A and B, 17 patients each group. There was no significant difference in gender, age, side, body mass index, cause of injury, injury to operation time, and fracture AO classification between groups ( P>0.05), with comparability. All patients underwent fixation with interlocking intramedullary nail, and the new tail cap and original tail cap were used in groups A and B respectively. The blood loss and operation time during tail cap implantation, fracture healing time, and complications were recorded and compared between 2 groups; the limb function was evaluated by Klemm function evaluation standard.
Results: The blood loss and operation time during tail cap implantation of group A [(3.5±0.8) mL and (10.57±3.15) s] were significantly less than those of group B [(5.5±1.7) mL and (21.99±6.90) s] ( t=-8.281, P=0.010; t=-10.743, P=0.009). All new tail caps were successfully implanted by one-time in group A, and the one-time success rate was 100%; the original tail cap exfoliation occurred in 3 cases of group B, and the one-time success rate was 82.4%. All the patients were followed up 6-16 months (mean, 9.7 months); there was no deep infection, loosening or breakage of internal fixation, and other serious complications. The time of fracture healing was (16.4±3.2) weeks in group A and (15.8±3.5) weeks in group B, showing no significant difference ( t=0.514, P=0.611). At last follow-up, according to the Klemm function evaluation standard, the results were excellent in 14 cases and good in 3 cases in group A, and were excellent in 11 cases and good in 6 cases in group B, showing no significant difference between 2 groups ( χ2=0.142, P=0.707).
Conclusion: The new type of femoral intramedullary nail tail cap can simplify operation, shorten operation time, and reduce blood loss, and it has satisfactory effectiveness.
目的: 研制一种用于封闭股骨交锁髓内钉中心孔尾端的新型尾帽，以减小尾帽植入髓内钉的难度，保证植入准确性，减少不必要的手术时间。.
方法: 2014 年成功研制出一种新型股骨髓内钉尾帽（以下简称“新型尾帽”）并获国家实用新型专利。采用临床随机对照研究，将 2014 年 8 月—2016 年 3 月收治的符合选择标准的 34 例非病理性股骨干骨折患者随机分为 A、B 两组，每组 17 例。两组患者性别、年龄、侧别、体质量指数、致伤原因、伤后至手术时间、骨折 AO 分型等一般资料比较差异均无统计学意义（ P>0.05），具有可比性。两组患者均行交锁髓内钉固定术，A、B 组分别采用新型尾帽和原配尾帽。术中测量并比较两组植入尾帽的出血量和手术时间，术后比较两组并发症发生情况和骨折愈合时间，采用 Klemm 功能评定标准评价两组患肢功能。.
结果: A 组植入尾帽过程的出血量和手术时间分别为（3.5±0.8）mL 和（10.57±3.15）s，均显著少于 B 组的（5.5±1.7）mL 和（21.99±6.90）s，差异有统计学意义（ t=–8.281， P=0.010； t=–10.743， P=0.009）。A 组新型尾帽均一次性植入成功，成功率 100%；B 组中 3 例原配尾帽旋入时脱落，一次性成功率 82.4%。两组患者均获随访，随访时间 6～16 个月，平均 9.7 个月。所有患者均无深部感染、内固定物松动或断裂以及其他严重并发症发生。A、B 组达骨折临床愈合时间分别为（16.4±3.2）周和（15.8±3.5）周，差异无统计学意义（ t=0.514， P=0.611）。末次随访时，根据 Klemm 功能评定标准，A 组优 14 例、良 3 例，对照组优 11 例、良 6 例，差异无统计学意义（ χ2=0.142， P=0.707）。.
结论: 新型股骨髓内钉尾帽使术中操作简便，手术时间缩短，出血量减少，治疗效果满意。.
Keywords: Femoral intramedullary nail; internal fixation; intramedullary nail tail cap.